Establishment of an orthotopic transplantable gastric cancer animal model for studying the immunological effects of new cancer therapeutic modules

Abstract

Tumor cell growth is influenced by the cellular microenvironment including the presence of immune cells and blood vessels. Currently, no transplantable gastric cancer syngeneic animal models exist; therefore, we set out to establish a mouse gastric carcinoma cell line, which was named mouse gastric carcinoma cell line 3I (MGCC3I), from forestomach carcinoma developed in benzo[a]pyrene-treated ICR mice. MGCC3I cells showed epithelial-like morphology, multinuclear giant cell formation, and retained an intestinal phenotype, which are similar to human gastric cancer carcinoma cells. The expression of gastric cancer markers MUC1, MUC2, and MUC5AC, and oncogenes c-myc, c-met, cyclin E1, and cancer stem cell marker CD44 was determined in MGCC3I cells. MGCC3I cells formed poorly differentiated stomach tumors following orthotopic implantation into the stomachs of syngeneic ICR mice. Histone deacetylase inhibitors are recognized as a new class of anticancer drugs. The immunological therapeutic effects of the histone deacetylase inhibitors sodium butyrate and valproic acid were evaluated in this new animal tumor model. Sodium butyrate inhibited MGCC3I stomach tumor formation in animal models. Increased tumor infiltration by CD8 T cells and neutrophils was observed in mice treated with sodium butyrate or valproic acid. Depletion of CD8 T cells significantly attenuated tumor regression mediated by histone deacetylase inhibitors, which is correlated with enhancement of the MHC class I pathway in MGCC3I cells. Taken together, we have successfully established an orthotopic transplantable gastric tumor animal model and demonstrated its usefulness in revealing the role of CD8 T cells in the therapeutic effects of sodium butyrate. ß

Mucin 2 silencing promotes colon cancer metastasis through interleukin-6 signaling

“…Total cell lysates were prepared and analyzed by SDS-PAGE as previously described 43 . For quantification, the bands were measured using an AlphaImager 2200 system (Alpha Innotech, San Leandro, CA, USA) and were normalized to the band density of β-actin.…”

“…The metastatic abilities of the HT-29 and CT26 cell clones in vivo were evaluated using a hepatic metastasis model, in which 1 × 10 6 tumor cells in 0.05 mL of PBS were injected intrasplenically as previously described 42, 43 . For more detailed information, please see the Supporting Information.…”

Suppression of mucin 2 promotes interleukin-6 secretion and tumor growth in an orthotopic immune-competent colon cancer animal model

“…Peptides used in this study were synthesized and purified by Genemed Synthesis (San Antonio, TX, USA). Total cell lysates were prepared and analyzed by SDS-PAGE as previously described (16). Immunodetection was performed using a horse-radish peroxidase (HRP)-based SuperSignal Chemiluminescent Substrate (Pierce, Rockford, IL, USA).…”

“…To characterize the immune cells of the peritoneal fluid in vivo , peritoneal fluid was isolated and subjected to flow cytometry as previously described (16,18). The following fluorescent-labeled antibodies were purchased from BD Bioscience: rat anti-Ly6G-FITC, anti-CD4-PE, anti-CD8-PE, anti-CD11b-PE and isotype controls (FITC and PE).…”

Anticancer potential of naturally occurring immunoepigenetic modulators: A promising avenue?

“…Several HDACi agents upregulate the expression of genes involved in APM or costimulatory molecules by tumor cells . Shan et al reported that butyrate induces the expression of many APM‐related genes, including histocompatibility 2, D region locus 1, tapasin, transporter associated with antigen processing (TAP1) and TAP2, low‐molecular‐mass protein 2 (LMP2) and LMP7, and MHCI on the cell surface of MGCC3I carcinoma cells . These results probably are explained by the direct effect on HDAC activities associated with subsequent transcriptional activation, because many HDACi agents, including SAHA, reportedly upregulate the expression of APM‐related genes .…”